A legendary individual, who will stop at nothing to get his/her way. Usually used in the context of pursuing members of he opposite sex, drinking vast amonts of alcohol or pushing physical and mental powers to the limits. Showing general doggedness is a requirement.

"He pulled seventeen girls last night, he's such a terrier"
"I drank twenty pints, didn't have any sleep and now I'm at work, I'm such a terrier"
" won't have a blue WKD thanks, I'm far too terrier-like"

Terriers was a crime drama on FX back in the autumn of 2010. You probably didn't watch it. If you did, you would quickly realise it was the best show on TV. But sadly, it got cancelled. However, it managed to have a perfect single season.

The show was a comedy-drama about two unlicenced Private Investigators in San Diego. One is a recovering alcoholic, and the other a former criminal. It is kind of like Veronica Mars, only with adults.

Man, I started watched that tv show Terriers last night. Why didn't you tell me about it sooner?